2002 Genie S-65 Wont Drive In High Speed???

[Chris Muller]

I have a 2002 Genie S-65 and it will only operate in slow speed (vehicle moving). This is also the first Genie lift I have ever worked on so this is a learning curve. I have the workshop/electrical manual for the genie and Im at a loss for whats causing this issue.

any help would be greatly appreciated.

Genie Serial Number #s60-8369

 

[92U 3406]

There are a few conditions that cause the machine to be stuck in slow speed:

Boom is elevated too high. A faulty or misadjusted limit switch for the boom height can cause the machine to think the boom is raised when it actually isn't.

Boom telescoped out. Again could be a faulty or misadjusted limit switch telling the machine the boom is telescoped when it isn't.

 

[Chris Muller]

I have disconnected the orange wire (pin 6) inside the horse power limiter board as to bypass the limit switches (if the problem was the switches the machine would have run at full speed, it did not). Then I removed the red wire (pin 10) and jumped it to the white wire (pin 1) as to bypass the horse power limiter board (if the problem was the limiter electrical board itself then the machine would have run at full speed, it did not)

the RPM of the engine is increasing when I step on the foot pedal. this could have potentially been another issue as the drive motor will not allow full speed if the engine is under load such as going up a hill.

I have been all over this unit and im at a loss as to what is causing the issue. I bench tested the low speed high speed switch itself and according to the manual the continuity paths are functioning correctly on the switch indicating the switch itself is ok.

there just seems to be so many factors that can result in the machine not operating at full speed, im probably missing one and that's the cause of my problem, im just not sure where to head next.

 

[Johndoe]

Horsepower limiter boards 101:
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All test performed with engine running in high idle with the unit in low torque mode (flat ground mode)
Terminal
1- Power input (Needs to be greater than 12vdc while engaging drive)
2- Ground (When in doubt, run a new ground from the battery all the way up to this terminal. Will need about 20+ feet of known good wire)
3- Tach signal (Needs to be greater than 100Hz)
4- Not used
5- Not used
6- Limit switch input ( limit switches provide a ground when "off limit". Removing the wire will eliminate the limit switches)
7- Not used
8- Not used
9- Not used
10- Output to joystick (check power here and at the joystick)
Trim Pots (top to bottom)
A- Used to adjust stowed drive speed (set to 10.5-10.5vdc while driving)
B- Elevated "Off limit" drive speed ( set to 1 foot per second )
C- Anti stall (Only play with this if the unit is surging in high idle while driving in flat ground)

 

[Chris Muller]

Wow was this a **** luck fix... Im going through the manual and checking the limit switches and checking the horsepower board and at no point does the repair manual ever point you towards a hydraulic block containing 2 solenoids right beside the main hydraulic pump on the engine side. Its here where I was looking at the hydraulic pump and noticed a red wire had slipped off one of the solenoids. The electrical connection is just a female spade connector and it snugs onto the male spade on the solenoid coil itself. Plugged the wire back in and ka-boom, everything works correctly. Just wish I didn't spend so much time chasing the horsepower limiter board and the limit switches, even right now im not sure exactly what those solenoids do I just know that they need to be plugged in lol

 

[Johndoe]

Wow was this a **** luck fix... Im going through the manual and checking the limit switches and checking the horsepower board and at no point does the repair manual ever point you towards a hydraulic block containing 2 solenoids right beside the main hydraulic pump on the engine side. Its here where I was looking at the hydraulic pump and noticed a red wire had slipped off one of the solenoids. The electrical connection is just a female spade connector and it snugs onto the male spade on the solenoid coil itself. Plugged the wire back in and ka-boom, everything works correctly. Just wish I didn't spend so much time chasing the horsepower limiter board and the limit switches, even right now im not sure exactly what those solenoids do I just know that they need to be plugged in lol

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your looking at the brake and two speed manifold

Brake valve= Red/White (gets power when unit is driving)
Two speed valve = White/Red (gets power when unit is in high speed/ Low torque drive)